COBE Diffuse Background Experiment Observations of the Galactic Bulge
Abstract
Low angular resolution maps of the Galactic bulge at 1.25, 2.2, 3.5, and 4.9 micrometers obtained by the Diffuse Infrared Background Experiment (DIRBE) onboard NASA's Cosmic Background Explorer (COBE) are presented. After correction for extinction and subtraction of an empirical model for the Galactic disk, the surface brightness distribution of the bulge resembles a flattened ellipse with a minor-to-major axis ratio of approximately 0.6. The bulge minor axis scale height is found to be 2.1 deg +/- 0.2 deg for all four near-infrared wavelengths. Asymmetries in the longitudinal distribution of bulge brightness contours are qualitatively consistent with those expected for a triaxial bar with its near end in the first Galactic quadrant (0 deg less than l less than 90 deg). There is no evidence for an out-of-plane tilt of such a bar.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- April 1994
- DOI:
- 10.1086/187315
- Bibcode:
- 1994ApJ...425L..81W
- Keywords:
-
- Barred Galaxies;
- Galactic Bulge;
- Galactic Structure;
- Infrared Astronomy;
- Milky Way Galaxy;
- Cosmic Background Explorer Satellite;
- Galactic Evolution;
- Interstellar Extinction;
- Near Infrared Radiation;
- Spaceborne Astronomy;
- Astronomy;
- GALAXY: STRUCTURE;
- INFRARED: GALAXIES